In approximately 90% of all cases a pheochromocytoma causes sustained or paroxysmal hypertension. During surgical resection tumor manipulation can lead to excessive catecholamine release with the risk of life-threatening complications. Since the early 1950s a preoperative medical treatment with an α-adrenoceptor blocking agent has been successfully administered for prevention of hemodynamic instability but not all pheochromocytomas are associated with hypertension. Currently the discovery of asymptomatic pheochromocytomas is more frequent than in the time prior to modern imaging techniques (computed tomography, magnetic resonance imaging). There is little information about this type of pheochromocytoma in the literature. This article discusses the question if preoperative α-adrenoceptor block is also indicated in asymptomatic pheochromocytomas based on the current literature.